The invention relates to commercial-scale food product coating apparatus and, more particularly, to coating apparatus adapted for a high-moisture content, gauzy coating material such as and without limitation Panko-style, Japanese-introduced bread crumb.
On the date accessed as given next, the online encyclopedia “Wikepedia” had an article on what is Panko. http://en.wikipedia.org/wiki/Panko (accessed Jan. 5, 2012). It recites in part:—                Panko is a variety of flaky bread crumb used in Japanese cuisine as a crunchy coating for fried foods, such as tonkatsu. Panko is made from bread baked by passing an electric current through the dough, yielding bread without crusts, and it has a crisper, airier texture than most types of breading found in Western cuisine. Outside Japan, it is becoming more popular for use in Asian and non-Asian dishes, is often used on fish and seafood, and is often available in Asian markets and specialty stores. Increasingly, it is also available in many large supermarkets. Panko is produced worldwide, particularly in Asian countries, including Japan, Korea, Thailand, China, and Vietnam.        
From the perspective of a long-experienced designer of commercial-scale coating apparatus for food products (eg., the inventor hereof), there are many more things to say about Panko than just that.
To date, food product coating material for commercial-scale food process lines has typically been either a substantially dry particulate (eg., flour, spices, desiccated bread crumbs, mixtures thereof and the like) or else a substantially thick viscous fluid (eg., batter). A machine which can handle one typically cannot handle the other. For example, contrast food coating apparatus for dry particulate, such as:—    U.S. Pat. No. 6,158,332—Convertible drum-type coating apparatus (Nothum, Sr., et al.), or    U.S. Pat. No. 7,231,885—Food coating and compressor apparatus (Nothum, Jr., et al.),to food coating apparatus for batter, such as:—    U.S. Pat. No. 6,510,810—Convertible combination batter mixer and applicator machine (Nothum, Sr., et al.).Aong with U.S. Pat. No. 6,305,274—Fryer for Food Process Lines (Nothum, Sr., et al.), the foregoing patent disclosures are incorporated herein in full by this reference thereto.
Panko—as a coating material—has properties which distinguish it greatly from both dry particulate (on one extreme) and thick viscous fluids (at the other extreme). Panko poses several challenges for the designer of commercial-scale food coating apparatus. In the spectrum of coating materials between dry particulate and thick viscous fluids, it definitely lies in the middle:—in a class by itself.
Panko somewhat resembles in appearance and gauziness something like loose-fill blown-in insulation, except Panko has a high moisture content. Put differently, Panko is like a lot of smallish cotton tufts, except (again), Panko has a high moisture content. The freshest Panko has moisture contents of anywhere from about 40 to 50% (forty to fifty percent). It can be squished easily into doughy cakes or lumps. However, Panko can be dried to reduce its moisture content.
And it is believed that the prior art solutions to handling Panko-like materials in commercial food product coating apparatus have done just that. That is, Panko was dried in an oven or otherwise dried to get the moisture content down to where the material will run through a machine which is substantially designed for a dry particulate coating material.
Properly fresh and moist Panko (wet Panko) will not run through such machines. Indeed, fresh moist Panko will clog up both kinds of machines which are conventionally designed for (i) coating with dry particulate or, at the other extreme (ii) coating with a thick viscous fluid (batter).
For dry particulate material, the inventor hereof ordinarily prefers to design conveyors with either (1) open wire mesh construction, or else (2) drag-link construction. For an example of open wire mesh construction, see U.S. Pat. No. 6,305,274—Nothum, Sr., et al., and FIG. 6 therein. For an example of drag-link construction, see U.S. Pat. No. 6,158,332—Nothum, Sr., et al., and FIG. 4 therein.
With either conveyor construction, and when motivating dry particulate material in the direction of conveyance, both those kinds of conveyors typically have their coating-material motivating runs scraping over a solid support panel. Dry particulate material is easily conveyed by such conveyor constructions.
The problem with Panko and Panko-like materials for open wire mesh construction is the following. That is, Panko will stick fast to the underlying support panel. Then the Panko builds its own ramp. Pretty soon, the wire mesh belt is running on top of the mound of Panko—and not directly scraping across the underlying support panel.
Again, an accretion of Panko gets in between the belt and the underlying support panel, and this frustrates the purpose of the wire mesh belts. Belts can become over-tensioned to the point of overwhelming the drive power of the motors or drive transmission components. Also, the mound of Panko does not clean off easy. It cleans off as difficult as plaster, posing concerns for sanitary standards.
The other conveyor option for dry particulate material is typically drag-link conveyors, which have open cells (or pockets). If Panko were run through a drag-link conveyor, it would gum up the inside niche of each of the open cells (or pockets). The stuck and drying Panko would form a cemented solid inside each such niche of each cell or pocket. That might not only cripple the machine, but also the gummed-in Panko would be difficult to clean out. The machine would be inoperable again, and unsanitary as well.
Fluid handling apparatus are, needless to say, fluid handling apparatus. See, eg., U.S. Pat. No. 6,510,810—Convertible combination batter mixer and applicator machine (Nothum, Sr., et al.). For fluid handling apparatus, there are plumbing conduits with elbows and valves:—elements which pose a possible place for flowing semi-solids that readily squish, to squish so, and let their moisture content squeeze out. Thereafter, the squished semi-solid silts up, gums up, and, hardens. Panko does just that. Panko is not a fluid.
What is needed is a coating apparatus for food product which accommodates substantially most of the challenges of handling a coating material like Panko, which is neither a dry particulate nor else a fluid (however thick).